The field of the invention generally relates to electrical jacks, and more particularly to jackfields which include a plurality of jacks in a jack housing or jack panel.
There is widespread usage of electrical jacks that have switches activated by inserting plugs through jack sleeves in the face plate of each jack. For example, one type of jack which is commonly referred to as a tri-jack has a vertically elongated face plate with three vertically aligned jack sleeves. Commonly, the top jack sleeve is used for monitoring the jack circuit, while the bottom two jack sleeves are used for interconnecting circuits such as between different tri-jacks using a patch cord with plugs on the ends. The circuits are typically digital or voice frequency and are used in such applications as, for example, telephone central offices, testing and patch panels, computer and data processing equipment, multiplex gear, and commercial and industrial patching and control applications.
Commonly, a jackfield has input and output circuits connected at the back, and the front is covered by a panel that has apertures through which the individual jack sleeves extend so that patch cord plugs can be inserted. One such jackfield is described in U.S. patent application Ser. No. 14,909, filed Feb. 13, 1987. It has significant advantage over earlier jackfields because, among other reasons, the tri-jacks have rearwardly extending pins that insert into a connector of a printed circuit board. Accordingly, the tri-jacks can easily be removed and replaced without disconnecting and reconnecting hard wiring such as wire wraps. This feature is particularly important because the tri-jacks have a higher failure rate than the other jackfield components due to their moving mechanical switches. Accordingly, the tri-jacks have to be replaced more often. Also, tri-jacks are changed in order to alter the circuit configuration of the tri-jack. However, one drawback of the above-described jackfield is that before the tri-jacks can be removed or inserted, the patch cords have to be removed so that the front panel can be taken off to expose the tri-jacks. This means that any time a tri-jack is to be removed or replaced, all of the patch cord interconnected active circuits must be disrupted.